Table 2. --Mean timelags for needles and litter beds of ponder os a pine needles based on 

 the time for 95 percent of total change 





Physical properties 





Response 



time 



data 











: Initial 



: Final 



Arith 





: Standard 



:No. 













Packing : moisture : moisture 



metic 



: devia- 



: of 



: Standard 



Materi al 



Thickness : 



Density : 



ratio : content 



: content 



mean 



tion 



: runs 



: error 







Cm 



G/cc 



_ _ _ 



- Vercent - - 





Min - 







Min 











DESORPTION 



WITHOUT SOLAR 















Needles 







0695 



0.51 



1.0 23 







7.2 



251 . 



4 



48 



6 



5 



21.8 



Bed 



2 







. 005 



0.0098 23 







7.2 



309. 



8 



16 



7 



3 



9. 7 



Bed 



2 







.015 



.0294 23 







7.2 



350. 



4 



48 



2 



6 



19.7 



Bed 



2 







.045 



.0882 23. 







7.2 



332 . 



8 



56 



8 



3 



32 . 8 











ADSORPTION 



WITHOUT SOLAR 















Needles 





0695 



.51 



1.0 7 



2 



23.0 



242. 



6 



79 



9 



5 



35.7 



Bed 



2 







.005 



.0098 7 



2 



23.0 



333. 



1 



91 



8 



I 



64 . 9 



Bed 



2 







.015 



.0294 7 



2 



23.0 



385. 



4 



40 



2 



6 



16 . 4 



Bed 



2. 







.045 



.0882 7 



2 



23.0 



314 . 



5 



14 



4 



3 



8.3 











DESORPTION 



WITH SOLAR 















Bed 



2 







.005 



.0098 25. 







7.2 



243. 



3 



70 



4 



4 



35 . Z 



Bed 



2 







.015 



.0294 23 







7.2 



206. 



2 



54 



6 



5 



24 . 4 



Bed 



2 







.045 



.0882 23 







7.2 



154. 







24 



5 



4 



12 . 3 











ADSORPTION 



AFTER SOLAR 















Bed 



2 







.005 



.0098 7 



2 



23.0 



382. 



9 



54 



6 



4 



27. 3 



Bed 



2 







.015 



.0294 7 



2 



23.0 



406. 



8 



27 



3 



5 



12.2 



Bed 



2 







.045 



.0882 7 



2 



23.0 



411. 



3 



18 



1 



4 



9.1 



The results for needles suggest nearly equal response times for desorption and 

 adsorption. This timelag of 4.2 hours agrees with the needle timelag reported by 

 Fosberg (1975) of 4.1 hours for freshly fallen ponderosa pine needles, as supplied by 

 Blackmarr (1971). Data for other conifer needles, freshly cast, show variation in 

 timelags : 



Species 



Timelag Drying condition 



Reference 





Hours 



°F Percent 













relative 













humidity 







Lodgepole pine 



17.5 



80 



20 



Blackmarr, in Fosberg 



(1975) 











(supported by our own 



tests) 



Red pine 



10.5 



78 ±2 



35 ±5 



Van Wagner (1969) 





Red pine 



21.5 



78 ±2 



55 ±5 



Simard (1968b) 





Eastern white 













pine 



17.5 



78 ±2 



55 ±5 



Simard (1968b) 





Jack pine 



16.5 



78 ±2 



55 ±5 



Simard (1968b) 





White spruce 



15.0 



78 ±2 



55 ±5 



Simard (1968b) 





13 



